Copper-zinc alloy

ABSTRACT

A copper-zinc alloy includes 56-65%, by weight, of copper (Cu), 0.2-1.5%, by weight, of Tin (Sn) for improving tensile strength of copper (Cu) and for strengthening the corrosion resistance of Zinc (Zn), 0.1-1.0%, by weight, of Aluminum (Al) for ameliorating the yielding and tensile strength and corrosion resistance of the alloy, 0.01-0.6%, by weight, of Nickel (Ni) for improving the yielding and the tensile strength and the resistance and the heat conductivity of the alloy, lower than 0.5%, by weight, of Ferrite (Fe), 0.05-2.0%, by weight, of Antimony (Sb) for strengthen cutting ability and improving corrosion resistance, with the balance being zinc (Zn) and inevitable impurities.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to the lead free Copper-Zinc alloy, which particularly focuses on decreasing the cost of the lead free Copper-Zinc alloy to prevent the Copper-Zinc alloy from polluting our environment and improving mechanical ability.

2. Description of the Prior Art

Typical copper-zinc alloys comprise a number of materials, such as Iron (Fe), Aluminum (Al), Tin (Sn), Nickel (Ni), and inevitable impurities for increasing the corrosion resistance, strengthen tensile, or the like.

For example, U.S. Pat. No. 4,990,309 to Miyafuji et al. discloses one of the typical high strength Copper-Nickel-Tin-Zinc-Aluminum alloys containing Nickel (Ni), Tin (Sn), Aluminum (Al), Manganese (Mg), Zinc (Zn), Chromium (Cr), the balance of copper and inevitable impurities.

The typical high strength Copper-Nickel-Tin-Zinc-Aluminum alloy contains a large amounts of the copper up to 80% in terms of weight. However, the copper is an expensive material that may greatly increase the cost of the alloy and that may greatly reduce the competition of the alloy.

U.S. Pat. No. 5,658,401 to Gaag et al. discloses another typical Copper-Zinc alloy for semi-finished products and articles which are highly loaded and subjected to extreme wear especially synchronizing rings.

However, the typical Copper-Zinc alloy comprises the Lead (Pb) which is toxic may damage worker health during producing Copper-Lead-Zinc alloy and will also release toxicity into drinking water which will damage human health and pollute our environment.

U.S. Pat. No. 7,128,871 to Davitz discloses a further typical silver-colored, tarnish-resistant, corrosion-resistant alloy with low percentages of copper and zinc for jewelry items, tableware items, dental items or other items that should resist tarnishing or corrosion and which require a non-brittle alloy.

However, the typical silver-colored alloy includes a large amount or percentage of the silver up to about 92-95% in terms of weight which is an expensive material that may greatly increase the cost of the alloy and that may greatly decrease or reduce the competition of the alloy.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional copper-zinc alloys.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a Copper-Zinc alloy to reduce amounts of Copper material for decreasing the cost of the Copper-Zinc alloy and without any lead engaged therein for preventing the Copper-Zinc alloy from polluting our environment or damage human health.

In accordance with one aspect of the invention, there is provided a Copper-Zinc alloy comprising 56-65%, by weight, of Copper (Cu), 0.2-1.5%, by weight, of Tin (Sn) to improve the tensile strength and the corrosion resistance of Zinc (Zn), 0.1-1.0%, by weight, of Aluminum (Al) to strengthen yielding strength and the corrosion resistance of the alloy, 0.01-0.6%, by weight, of Nickel (Ni) to increase tensile strength and the corrosion resistance of Zinc (Zn) and the heat conductivity of the alloy, lower than 0.5%, by weight, of Iron (Fe). The alloy also comprises a secondary material introduced into said alloy, which is 0.01 to 2.0%, by weight, of Antimony (Sb). Antimony (Sb) could increase the mechanical ability and corrosion resistance of the alloy. Antimony not only improves mechanical ability but also strengthen the corrosion resistance of alloy. And the remaining percentage is Zinc (Zn) with inevitable impurities.

Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein below, with appropriate reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A Copper-Zinc alloy in accordance with the present invention primarily comprises a Copper material (Cu), which is composed of 56 to 65 percent in terms of weight that is relatively lower than that contained in the other invention related to Lead Free Copper-Zinc alloys to decrease the cost of the Lead Free Copper-Zinc alloy.

The alloy also contains Aluminum (Al), which is 0.1-1.0 percentage, by weight, that could strengthen the yielding strength and the corrosion resistance of the alloy. However, it may slightly decrease the ductibility of the alloy. Too much percentage of Aluminum (Al) may weaken the stretchability of the alloy. In addition, the specific gravity of Aluminum (Al) is relatively lighter than specific gravity of the other Copper-Zinc alloy. Adding a specific amount of Aluminum (Al) may relatively decrease weight of alloy. Both Aluminum (Al) and Tin (Sn) could strengthen the cutting property of the alloy.

The alloy also may comprise Iron (Fe) which could be well mixed the particle of the alloy. However, Iron (Fe) which contain too much inside alloy may weaken the property of corrosion resistance. Therefore, alloy could not contain too much percentage of Iron (Fe) therein. And the amount of Iron (Fe) is preferably no more than 0.5%, in terms of weight. The alloy may further comprise unavoidable impurities therein.

The alloy which comprises Nickel (Ni) which may even particle of the alloy, strengthen yielding strength, tensile strength, corrosion resistance and heat conductivity of the alloy. Besides, the microstructure which is composed of Nickel will be more uniform after heating or extruding. The percentage of Nickel ranged preferably between 0.01 to 0.6 percentages, in terms of weight.

Tin (Sn), including 0.2-1.5% in terms of weight, may improve the tensile strength and the elongation property of Copper (Cu) and may also strengthen the corrosion resistance of Zinc (Zn). The amounts of Tin (Sn) is preferable no more than 1.5%. The cutting effect and the corrosion resistance of the alloy may be suitably improved when the amount of Tin (Sn) reaches 1.0%, the corrosion speed of zinc (Zn) will reach about 0.0115 mm/Hr when the amount of Tin (Sn) reaches 1.5%, the more Tin (Sn) the better the cutting effect and of the alloy and the better the corrosion resistance of the alloy. However, Tin (Sn) is more expensive than the other anti-corrosion materials, such that the amount or percentage of tin (Sn) is preferably ranged between 0.2-1.5% in terms of weight.

Without Phosphorus (p) and Arsenic (As), the alloy may comprise other material, which is Antimony (Sb) added therein. Antimony (Sb) is composed of amount between 0.05-2.0% in terms of weight and may improve the cutting effect of the alloy, when it is introduced.

Antimony (Sb) is close related to copper (Cu) and may generate Sb₂S₃ and/or Sb₂O₃, and is heat and electricity resistive, when Antimony (Sb) is introduced into the alloy, the corrosion resistance of the alloy will be suitably strengthen and the oxidization of the alloy will be suitably decreased. Antimony (Sb) is not easily melted into Copper (Cu) and may not affect the heat conductivity and the electric conductivity of the alloy, but may harden the alloy that the working ability of plasticity, machining, forging of the alloy may be affected. The solid solubility of Antimony (Sb) will be around 5.9% when heating temperature reach to around 630° C. and will be gathered in crystal for allowing Antimony (Sb) to be uniformly distributed in crystal.

The cutting effect and the corrosion resistance of the alloy may be obviously improved when the amount of Antimony (Sb) is more than 0.2%, and the working ability for plasticity, machining or forging may weaken when the amount of Antimony (Sb) is more than 1.5%, and the fragile or brittle characteristic of the alloy may strongly occur when the amount of Antimony (Sb) is more than 2.0%, and the alloy may be easily broken. Therefore, the amount of Antimony (Sb) contained in alloy is ranged between 0.05-2.0%,

The remaining balance of the alloy is Zinc (Zn), which may remarkably decrease heating conductivity and electric conductivity. However, composed of Zinc could improve yielding strength. When contained amount of Zinc (Zn) is more than 20%, the corrosion may be occurred in humid environment or in sea, particularly when the environment contains Ammonia (NH₃). The cutting effect of the alloy will be improved when the percentage of Zinc (Zn) is more than 33%. Too much Zinc (Zn) may decrease the malleability of the alloy. More than 45% of Zinc contained in alloy will be no economic value. In this invention, to solve corrosion problem is to increase composition of Nickel, Aluminum and Tin instead of decreasing composition of Zinc.

Accordingly, the Copper-Zinc alloy in accordance with the present invention includes a reducing amount of copper material for decreasing the cost of the Copper-Zinc alloy and including no lead engaged therein for preventing the Copper-Zinc alloy from polluting our environment.

Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. 

1. A copper-zinc alloy comprising: 56-65%, by weight, of Copper (Cu), 0.2-1.5%, by weight, of Tin (Sn), 0.1-1.0%, by weight, of Aluminum (Al), 0.01-0.6%, by weight, of Nickel (Ni), lower than 0.5%, by weight, of Iron (Fe), 0.05-2.0%, by weight, of Antimony (Sb), with the balance being Zinc (Zn) and inevitable impurities. 